Peristaltic pumps for moving fluids through flexible tubing are known in the art and have found particular application in the medical sciences both for moving biological fluids and for administering therapeutic agents. Typically in such peristaltic pumps, a rotor is mounted eccentrically on a shaft so that rotation of the shaft causes the rotor to transcribe an orbital path in which it is intermittently brought into pressure contact with a flexible length of tubing to compress the tubing and thereby force liquid through the tubing. Pumps of this type are, for example, described in U.S. Pat. No. 4,559,040 to Horres et al. which shows a peristaltic pump having a segmented stator chamber and U.S. Pat. Nos. 4,540,351 and 4,631,007 both to Olson describing peristaltic pumps which are provided with hinged jaws to permit insertion and removal of the flexible tube carrying the liquid being pumped.
As exemplified by the prior art described above, one of the problems encountered with peristaltic pumps is the complexity of the mechanism for holding the flexible tubing in the pump against the rotating pressure member. While it is necessary during the pumping operation for the flexible tubing to be held securely in the pump against a rigid surface so that the orbiting rotor can compress the tubing and move the liquid along within it, it is also desirable to provide a mechanism which permits rapid and easy removal or insertion of the flexible tubing without requiring complex disassembly or reassembly procedures. This is a particularly important and critical feature when the peristaltic pumps are being employed as positive displacement pumps in a medical environment either for transporting or measuring biological fluids or to meter liquid therapeutic agents since the attending physician or his assistants are unlikely to have the time or attention to become involved in extensive manipulative procedures and must depend on metering and volumetric measurements from a positive displacement pump designed for this use.
It is accordingly an object of the present invention to provide a peristaltic pump having a closure mechanism which permits quick and easy insertion and securing of a flexible tube carrying the liquid to be pumped, the closure member being provided with cams to keep the tube from "walking" during the pumping operation. It is a further object of the present invention to provide a peristaltic pump having a release mechanism which permits quick and efficient removal of the flexible tube from the pump without requiring dismantling or disassembly of the pump structure.